Generally, in a single-hull type planing boat, as the speed of the boat increases, the center of lift shifts too much toward the stern with respect to the center of gravity, causing a porpoising and a large pitching, making the traveling unstable.
On the other hand, in a 3-point-support type planing boat whose forepart is supported by two planing portions and its afterpart is supported by one planing portion, the center of gravity is located between three front and rear lifts even when the speed of the boat increases. This prevents a porpoising and a large pitching, realizing a stable planing on the surface of water.
In the latter type, however, since the number of planing portions in the forepart of the hull is greater than that in the afterpart, the ability of making a turn is degraded. Another drawback is that since only one planing portion is provided in the afterpart, it is difficult to mount two or more engines. Furthermore, there is a limitation in the arrangement of the cabin space.